The aims of the research proposed here are to investigate current hypotheses of colon cancer etiology and to explore associations between other potential risk factors and subsite-specific colon cancer. The following hypotheses will be tested: (1) dietary patterns, including high fat, high meat, low vegetable (particularly cruciferae) consumption are positively associated with risk of colon cancer; (2) cholecystectomy is positively associated with right-side colon cancer. A unique feature of the study is the ability to examine the independent and joint contributions of both dietary patterns and cholecystectomy to subsite-specific colon cancer risk. Other potential risk factors to be explored include urban living and residential migration, additional dietary items, history of intestinal disorders, medicinal drug use, body weight dynamics, socioeconomic status, and ethnicity. To accomplish these goals, a case-control study of subsite-specific colon cancer is proposed. The study will be based primarily on data recently collected from a large statewide sample; additional data will be obtained from medical records. The study will compare 400 colon cancer cases to 400 controls with cancer of sites other than gastrointestine or breast, and 400 general population controls. Multivariate logistic regression models will be used to estimate odds ratios for the above factors. In addition, exploratory studies that utilize the available data set will be conducted. Because the incidence of both colon and breast cancer are correlated with some of the same risk factors, a case-control study of breast cancer and dietary patterns, socioeconomic status, and urban living is also proposed. The sample will consist of 300 breast cancer cases, 300 controls with cancer of sites other than gastrointestine, and 300 general population controls. The availability of data on lifetime residential histories offers the special opportunity to investigate the cumulative and temporal nature of urban living as a risk factor for colon and breast cancer, and to investigate mobility patterns. The results will be of further use in assessing misclassification error due to mobility in studies of cancer rates by geographic area. The results of the proposed research are expected to contribute toward understanding the etiology of colon cancer and toward the identification and quantification of risk factors, with the eventual goal of reducing the incidence of this disease.